I had surge brakes installed on my second trailer. I also had an auxiliary diesel tank in the bed to avoid fueling issues. Did still encounter a couple times when we had to pull into a large parking lot and drop the second trailer, fuel and then hook back up.
I made a point to be completely legal and talked with CHP, local PD, and the DMV so as to avoid any issues. Did have a few conversations with DOT officers in CA while towing and they were all good to deal with. Oregon highway patrol was having lunch at the same diner we were at and did question the legality of our set up but as soon as they heard we were headed back to CA they were no longer interested :).
I don't see myself doing it again any time soon but wouldn't hesitate to do it again. It is a great way to RV and have a choice of toys or no toys.